diff --git a/composer.json b/composer.json
index 8a69a55..e7275e6 100644
--- a/composer.json
+++ b/composer.json
@@ -23,6 +23,6 @@
   },
   "require-dev": {
     "php": "^7.2",
-    "phpunit/phpunit": "^7.4"
+    "phpunit/phpunit": "^8.5.52"
   }
 }